The Stars Aligned for This Three-Station SFN

Radio Magazine, By Mike Worrall, November 20, 2017

Nautel featured in this Facility Showcase article

KCSN and KSBR had to get creative to solve issues of mutual interference


We knew that the modulation levels at all three transmitters needed to be identical, as differences of less than 0.25 dB have been shown to raise the received noise floor dramatically. (This effect is discussed in Nautel’s webinar on SFNs, which can be viewed on YouTube)

Though several transmitter manufacturers offered AES-192 capability, we felt that Nautel was most appropriate, largely because of their pioneering work in enabling HD Radio broadcasts in SFNs — important because our SFN is committed to HD Radio. The Nautel user interface allows one to enable a micro-second resolution delay offset, vital in SFN’s for “moving” the inevitable interference area between transmitters.

Fast forward to NAB 2017, where we were talking Philipp Schmid about his experimentation with KUSC, and their booster in Santa Clarita, and how he overcame Xperi’s gen-four architecture to enable HD to work in SFNs.

We said, “Hey, Philipp. We’re down on our knees. We’ve got this SFN coming up. We really want to do HD. Are you comfortable allowing us to use Nautel’s HD SFN system? Is it a final product? Is it a product that we can buy?”

He said, “No. It’s not going to be ready until fourth quarter of this year.”

We said, “Oh gosh, we really would like to do this coming out of the box, but can’t wait until the fourth quarter. Will you allow us to use the beta version, or whatever version it is that you now have available here at the convention to come on with us as soon as we can?”

He said, “Yeah, sure.”

He’s just a good guy and was willing to help us out.